Evaporating apparatus.



:i REAEE E r P. KESTNER.

EVAPORATING APPARATUS. APPLICATION FILED AUG. 22', 1911.

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P. KESTNER. .EVAPORATING APPARATUS.

APPLICATION FILED AUG. 22 1911.

Patented June 4,1912.

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EVAPORATING APPARATUS.

APPLIOATION FILED AUG. 22, 1911.

; Patented June 4,1912.

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PAUL KESTNER, LILLE, FRANCE, ASSIGNOR T0 KESTNER EVAPORATOR COMPANY, OFPHILADELPHIA PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

EVAPORATING APPARATUS.

Specification of Letters Patent.

Patented June 4, 1912.

Application filed. August 22, 1911. Serial No. 645,427.

To all whom it may concern:

Be it known that I, PAUL KEs'rNnR, a citizen of the Republic of France,residing at Lille, Department of Nord, France, have PIELCUCG necessaryto use in each efiect a invented certain new and useful Improvements inEvaporating Apparatus, of which the following is a specification.

This invention relates to evaporating apparatus; and it comprises amultiple-liquid passage evaporating device having a plurality of sets ofevaporating tubes within a common heating casing and means whereby saidsets may be operated independently or successively, and, morespecifically, it comprises an evaporator or effect of the climbing filmtype having a plurality of sets of evaporating tubes for the ascent ofliquid therein, located and inclosed within a common heating jacket orcasing with connecting means allowing successive or independentoperation of the several sets; and it also comprises a combination of anevaporator or effect of the type described with other evaporators oreffects in multiple effect arrangement, said evaporator forming one ormore effects in said arrangement; all as more fully hereinafter setforth and as claimed.

In multiple effect evaporators of the traveling film type wherein liquidis passed, so to speak, as a flowing current through a series ofsuccessively operating evaporators, the volume of the liquid of coursebecomes progressively less as it passes forward. And since for a varietyof reasons it is desirable to have the successive evaporators or effectsof about the same dimensions, with a given amount of liquid flow in thefeed to the first in series, a fiow which will suffice to cover theheating surfaces to a given efficient depth, the fiow to the finaleifectwill,

necessarily, cover the heating surfaces there what is known as theclimbing film type of In any type of film evaporator it is in pluralityof heating tubes working in parallel and fed from a common source ofsupply;

and it is necessary that this liquid be divided with substantialequality among the several tubes. And this presents difficulties in thecase of the final effect where the vol- .ume of liquid fed in is andmust be materially lessened; it is difficult to keep the liquid fromdividing itself unequally among the several tubes, causing some to rundry and others to take an undue quantity.

In the present invention I have provided a modified type of evaporatorparticularly suitable as the final effect in a multipleefiect system. Asstated, it is desirable in practice that the final effect be about thesame dimensions as the others. As a matter of theory, in a tripleefiect, approximately the same amount of evaporation, that is,

production of vapors must occur in each effect; one-third of the totalvaporization must occur in each effect. There should therefore be aboutthe same area of evaporating surface; about the same area of surfaceexposed to heating vapors on the one side and to liquid to beconcentrated on the other. And since each succeeding effect is heated bythe vapors of the next preceding,

there should be vapor space in the heating elements ample to accommodatethe vapors from such preceding effect without back pressure. The vaporscoming from each prior effect must be condensed in the heating chambersof the next effect in such a manner as to allow the desired low pressureto prevail in such prior effect. This requires ample vapor space.

In, the present invention while retaining the size of the effect as awhole about the same as in the usual practice and giving it about thesame total vapor space in the heating chamber and total area ofevaporating surface, or of heat-transferring surface, I

subdivide this area into a plurality of distinct areas and provide meanswhereby said areas may be used successively or independently as regardsliquid to be concentrated or treated while supplying heating agentsimultaneously to all said areas, using a com mon heating casing orjacket for the grouped heat-transferring elements or areas. In a tubularevaporator provided with a plurality of evaporating tubes inclosed in acommon vapor-supplied heating casing or jacket, I group these tubes intoa plurality of sets, providing each set with special delivery means forliquid, or liquid and vapor, and with a special feed means. Suitableconnections allow liquid emerging from one such set to be re-deliveredto another such set for passage therethrough, or allow one or more setsto be cut out of operation altogether, or to be used for independentpurposes, as for preheating liquids. WVhere used for re-delivery,obviously since the liquid, so to speak, goes through the several groupsin series instead of in parallel, for a given rate of flow into theeffect the thickness of film, or covering, of liquid on the heatingsurfaces will be increased. Another advantage of this series feed isthat the speed of flow of the liquid over the heating surfaces isgreater than where the liquid is fed through the tubes in parallel.Other things being equal, the efliciency of heat transfer from a heatingsurface to a flowing liquid is the greater the more rapid the flow. Theadvantages of obtaining a more efficient thickness of film from a givenlimited amount of liquid are however independent of the seriesarrangement; and are attained when only part of the tubes instead of allare employed; i. e.,'when one or more groups or sets of tubes are cutout of circuit. Presuming there are two groups of tubes, the amount ofliquid which running in parallel through both groups may be somewhat toolittle to give an efficient film will still give efiicient filming ifitbe run through the two groups in series or if it be run through butone group. With a two-group apparatus used as an effect in a multipleeffect arrangement, one group may be used to evaporate the liquid goingthrough the multiple effect while the other is cut out altogether, notbeing supplied with liquid. The idle group does not absorb heat, theabsorption of heat being confined to the group in operation; or, inother words, the heat of the vapor supplied to the effect is utilizedwholly by the active group of tubes; that is, all the heat of the vaporsupplied whether steam or vapors from a prior effect is being utilizedby a limited number of tubes. On the other hand the other group insteadof being idle, may be utilized for heating or evaporating a dis tinctliquid, as for instance where a two group effect is used as the lasteffect in multiple effect: one group may be finishing the liquiddelivered by the next preceding effect while another group isfunctioning as a pre-evaporator on liquid to be delivered to the firsteffect in series. With a threegroup effect, two groups may be working inseries and a third group functioning as a pre-evaporator; or two groupsmay be working on independent liquids with the third group out out ofoperation; and so on.

Multiple group evaporators under the present invention may be usedassembled as any or all of the several effects of a multiple effectarrangement; but are particularly advantageous as the later efiects inseries because of the possibility of adjusting the area of heatingsurface functioning at any given time to the volume of the concentratedliquid delivered by prior effects without change of the heating elementsproper. The use of the multiple group evaporator as an effect in amultipleeifect arrangement, and particularly as the last effect, givesthe multiple effect assemblage great flexibility in operation. If allthe effects in the mul- 5 tiple effect are the present type ofmultiplegroup evaporator, the flexibility of the system as a whole isstill more enhanced. Presuming for example that the first efiect is amultiple-group evaporator, say with two groups, then one group may beused to do all the evaporation in the first effect, the other beingidle, giving a rapid delivery of a large volume of, relatively, littleconcentrated liquid to the second effect. Or the two groups may be runin parallel, delivering a double volume of such liquid to the secondeffect; and so on. With all the effects of multiple-group evaporators,any effect can, within limits, be run individually; the operation of theplurality of effects is not so interdependent as with the ordinary typesof multiple effects.

While the described multiple group arrangement of the evaporating'tubesin a single heating casing with feed arrangements of the type describedis applicable to many other types of tubular evaporators, such asstandard type or non-filming evaporators, evaporators working with adescending film, etc., I regard it as more particularly advantageouswith the ascending film type in which liquid travels upward throughtubes as an annular film under the influence of a quickly moving centralbody of vapor.

In the accompanying illustrationI have shown, more or lessdiagrammatically, certain embodiments of the. described invention.

In this showing, Figure 1 is a rather diagrammatic sectional view of anevaporator effect embodying the present invention and shown as of theascending film type; Fig. 2- is a cross section on the line waa of Fig.1 showing a vapor separator; Fig. 3 is a developed view on line 0-0,Fig. 5, of certain connections; Fig. 4 is a view similar to Fig.

and pipe connections which may be used; the piping for clearness ofillustration being shown on a smaller scale; Fig. 6 is a view inelevation of the, effect of Fig. 1 used as a final efiect andas apro-evaporator in a triple-effect assemblage; Fig. 7 is a horizontalsection on line m-m, Fig. 10, of a modified form of vapor separatorapplied to an efiect of the present improved type; Fig. 8 is ahorizontal section on line n-n, Fig. 9, of another form of vaporseparator for a two-section effect; Fig. 9 is a vertical section of thesame; and Fig. 10 is a view partly in vertical section and partly inelevation of the separator of Fig. 7.

Referring first to Figs. 1, 2, 3, 4 and 5, showing for the purposes ofillustration an evaporator of the climbing film type to which thepresent invention is particularly applicable, element 1 is a heatingshell or chamber fed with heating vapor through 2. At the bottom and topthis shell is spanned by cross headers 3 and 4. Through the bottomheader the tubes extend as tubular prolongations, projecting downwardlyinto basal feed chambers. As shown, these prolongations are providedwith laterally presented orifices, the tubes 5 being provided with abeveled end, as shown. This enables them to tap vapor and liquidsimultaneously, vapor entering at one level and liquid at anothersimultaneously. This much contributes to uniformity: of operation in aclimbing film evaporator.- Where such an evaporator is fed with heatedliquid, on entering the feed chamber self-evaporation takes place withthe formation of a layer of vapor above the liquid. As shown, there is afeed chamber 6 common to all the tubes and this feed chamber is providedwith radial partitions 7 which may be'in number sufficient to producetwo or more compartments, thereby subdividing the evaporator tubes intoa similar number of groups; one group for each such subchamber. Threecompartments and three groups are convenient. At the upper ends, theevaporator tubes open into a hood 8 for the separation of liquid andvapor. As shown, the hood is divided into three chambers A, B and C byvertical partitions 10 extending to a point near its top. Each of thesechambers corresponds to a group of evaporating tubes. Positioned somedistance above the tops of the tubes is a horizontal cross-partition 11of less diameter than the hood. The mixture of concentrated liquid andvapor emerging from the tops of the tubes in a group is caused to passlaterally into the hood by this partition, encountering a group ofvertical angle irons 12 (F ig. 2) which act as baffling elements,causing a separation of liquid. Passing beyond these baflie elements,the vapors pass again against groups of angle irons 13 (Fig.4) set inreverse posi tion, giving a further separation. Liquid separated abovethe cross partition drains back through pipes 16. All these compartments(A, B and C) are open at the top, the radial partitions not extendingthe full height of the hood, and they open under an eccentrically placedvertical wing battle 1.4, placed before the vapor outlet 15. Dams 15prevent backward passage of liquid. As stated, the effect shown issubdivided into three groups of tubes corresponding to the uppersubchambers A, B and C. Plpe connections are provided enabling thesegroups to be used in varied ways. Referring now more particularly toFig. 5, the groups are provided, respectively, with inlet-s a, b and 0to the lower chambers. From the upper chambers, return tubes 17, 18 and19, respectively remove the separated liquid and may return it to thebase of the next group in series. Since it is desirable to have bothvapor and liquid in the basal chamber of evaporators of this type inorder to facilitake the formation of the climbing film, and since thetubes of all the groups are heated to the same temperature andcommunicate with the same vacuum producing means, there is not asufficient drop of pressure on the liquid coming from the top of onegroup and going to the base of the next group to cause muchself-evaporation and formation of vapor to take place in such base. Forthis reason the return tube may be jacketed, as shown at 20 (return tube17 When this heating is used it is advisable to give the return pipe adepending bend (not shown) to facilitate circulation. The first returntube (17) is provided with a pair of valves 22 and 23, between which isplaced a T-connection 24, valved at 25 and functioning as a take-awayconduit. The second return tube is similarly provided with valves 26 and27, and T-connection 28, valved at 29; and the third return tube isprovided with valves 30 and 31 and T-connection 82, valved at 33. Liquidmay be brought to the apparatus through 3 4, having extensions, valvedrespectively at 35, 36 and 37, to each of the three inlets, a, Z) and c.Other liquid may be simultaneously introduced by pipe 38 havingextensions, valved respectively at 39, 40 and 41, to any of the threeinlets. This pipe by shutting valve 38 may also serve as a cross-overconduit being provided with connections valved at 39*, 4O and 41 withthe three T-connection pipes. A cross-pipe 42, has communications,valved respectively at 43, 44 and 45, with each of the return tubes,with valves, respectively 46, 47 and 48, in such return tubes below thepoint of communication. tiple group effect is to be run in but onepredetermined way of course many of these valves and tubes can bedispensed with; but the arrangement shown comprises connec- Vhere thedescribed mul group or groups, forms a convenient unit three groupseach, two groups in each evaporator can be operating while the third isbeing washed out. Each of the nine groups making up the threeevaporators can be washed out in succession while the other eight groupsare doing the work of evaporation. Referring to Figs. 1 and 2, forexample, A and B may be working in series or in parallel while cleanwater is being run through C. Group C is of course as hot as A and B andthe water runs through it rapidly cleansing it. In turn, evaporation maybe shifted to B and C and A cleansed and so on through each of theevaporators. Another convenience in the use of multiple groupevaporators in a multiple effect arrangement is that the sys tem may atwill be run at full capacity or less than full capacity. If eachevaporator be provided with four groups, obviously the system may be runat full capacity, at three quarter capacity, at half capacity, or atonequarter capacity. This power to run at less than full capacity isoften very convenient.

What I claim is 1. In an evaporator, a plurality of groups ofevaporating tubes, a common heating chamber inclosing said plurality ofgroups, a common offtake for the vapor formed in all said groups andmeans for passing liquid to be evaporated successively or independentlythrough said groups.

2. In an evaporator, three or more groups of evaporating tubes, a commonheating chamber inclosing said groups, a common offtake for the vaporsformed in all said groups, means for passing liquid to be evaporatedsuccessively through two such groups and means for passing liquidthrough another group independently of the circulation through the othersaid groups.

3. In a. climbing film evaporator, a plurality of vertical evaporatingtubes of a type adapted for climbing film evaporation, a common heatingchamber surrounding said tubes, a lower casing inclosing depending endsof said tubes, a partition in said casing dividing it into subchamberscommunicating with groups of said tubes, an upper casing at the top, apartition in said latter casing dividing it into a plurality ofsubchambers communicating with corresponding groups of said tubes, meansfor feeding liquid to one of the lower subchambers and means forreturning liquid from one of the upper subchambers to another of thelower subch ambers.

4. In a climbing film evaporator, a plu- I rality of vertical tubes, aheating chamber surrounding said tubes of a type adapted for climbingfilm evaporation, a surmounting hood having means for removing vaporfrom all said tubes, a casing inclosing depending ends of said tubes, aplurality of partitions in said casing dividing it into feedingsubchambers for corresponding groups of tubes, a plurality of partitionsin said hood dividing it into liquid-receiving subchambers communicatingwith corresponding groups of tubes, means for supplying liquid to one ofsaid feeding subchambers and means for withdrawing liquid from thecorresponding liquid-receiving subchamber.

5. In a climbing film evaporator, a plurality of vertical tubes, aheating chamber surrounding said tubes of a type adapted for climbingfilm evaporation, a surmounting hood having means for removing vaporfrom all said tubes, a casing inclosing de pending ends of said tubes, aplurality of partitions in said casing dividing it into feedingsubchambers for corresponding groups of tubes, a plurality of partitionsin said hood dividing it into liquid-receiving subchambers communicatingwith corre sponding groups of tubes, means for supplying liquid to oneof said feeding subchambers and means for withdrawing liquid from thecorresponding liquid receiving chamber and returning it to anotherfeeding subchamber.

6. In an evaporator, a plurality of evaporating tubes, a common heat-ingcasing inclosing said tubes, a vapor exit withdrawing vapor from allsaid tubes and means for feeding liquid independently or in seriesthrough different groups of said tubes.

7. In an evaporator, a plurality of evaporating tubes, a common heatingcasing inclosing said tubes, a vapor exit withdrawing vapor from allsaid tubes and means for alternately feeding liquid in series throughgroups of said tubes or for feeding liquids independently in parallelthrough said groups.

8. In an evaporator of the climbing film type, a plurality of parallelvertical evaporating tubes, a surmounting hood having means for removingvapor from all said tubes, and. means for feeding liquid inclependentlyor in series through different groups of said tubes.

9. In an evaporator of the climbing film type, a plurality of parallelvertical evaporating tubes, a surmounting hood having means for removingvapor from all said tubes, and means for alternately feeding liquid inseries through groups of said tubes or for feeding liquids independentlyin parallel through said groups.

10. In an evaporator, a plurality of vertical evaporating tubes of atype adapted for climbing film evaporation, a heating chamhersurrounding all said tubes, a liquid chamber inclosing depending ends ofsaid tubes, partitions therein subdividing it into a plurality ofsubchambers into which different groups of tubes open, a surmountinghood having a vapor-removing outlet and vertical partitions in said hoodextending to a point short of said outlet and dividing said hood into aplurality of liquid-receiving chambers corresponding to said groups oftubes.

11. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basal feedchamber into which depending laterally orificed prolongations open, apartition in said chamber dividing it into a plurality of subchamberscorresponding to difierent groups of said tubes, a surmounting hoodabove the upper ends of said tubes, a partition in said hood dividing itinto liquid-receiving subchambers corresponding to said tube groups, afeed connection to one of the basal subchambers and a liquid removingconnection to the corresponding liquid-receivingupper subchamber.

12. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basal feedchamber into which depending laterally orificed prolongations open, apartition in said chamber dividing it into a plurality of subchamberscorresponding to different groups of said tubes, a surmounting hoodabove the upper ends of said tubes, a partition in said hood dividing itinto liquidreceiving subchambers corresponding to said tube groups, afeed connection to one of the basal subchambers, a liquid transmittingconnection between the corresponding upper liquid receiving subchamberand another basal subchamber, and a liquid-removing connection from theupper liquid-receiving chamber corresponding to said other basalsubchamber.

13. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basalchamber into which depend prolongations of said tubes having laterallypresented orifices, partitions dividing said chamber into a plurality ofsubchambers corresponding to groups of said tubes, a hood chamber havingan exit for vapor and located above the upper delivery ends of saidtubes, partitions in said hood dividing it into liquid receivingsubchambers corresponding to said groups, and pipe-connections enablingliquid to be transmitted up? wardly through successive groups of tubesin series, liquid entering one of the basal subchambers and leaving froman upper liquid-receiving chamber.

14. I11 a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basal feedchamber into which depend prolongations of said tubes having laterallypresented orifices, radial partitions dividing said chamber into atleast three subchambers corresponding to an equal number of groups ofsaid tubes, a surmounting hood having an exit for vapors and dividedinto an equal number of corresponding liquid receiving chambers bysuitable partition and pipe connections by which liquid may betransmitted upwardly through two or three of said groups in series.

15. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basal feedchamber into which depend prolongations of said tubes having laterallypresented orifices, radial partitions dividing said chamber into atleast three subchambers corresponding to an equal number of groups ofsaid tubes, a surmounting hood having an exit for vapors and dividedinto an equal number of corresponding liquid receiving chambers bysuitable partitions and pipe connections by which liquid may betransmitted through two such groups in series while by-passing anothergroup.

16. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heat-ing chamber, a basal feedchamber into which depend prolongations of said tubes having laterallypresented orifices, radial partitions dividing said chamber into atleast three subchambers corresponding to an equal number of groups ofsaid tubes, a surmounting hood having an exit for vapors and dividedinto an equal number of corresponding liquid receiving chambers bysuitable partitions and pipe connections by which a liquid may betransmitted through two such groups in series and pipe connectionsenabling the simultaneous employment of another group for evaporatingliquid from another source of. supply.

17. In an evaporator, a plurality of efiects in multiple efl'ectarrangement treating liquid in series, the last of said efiects being ofthe climbing film type, having a plurality of relatively long verticalevaporating tubes and being provided with means for independentoperation of each of a plurality of groups of said tubes, and therebeing pipe connections enabling liquid to be transmitted through onesuch group and thence to the feed inlet of the first effect in serieswhile liquid from the next preceding efiect is being concentrated inanother such group.

18. In an evaporator of the climbing film type, a heating casing, aplurality of relatively long vertical evaporating tubes therein, basalfeeding means, a surmounting vapor-separating hood casing, means for 130discharging the vapor and liquid emerging from the upper end of saidtubes laterally within said hood and a plurality of vertical angle barsset within said hood in the path of said liquid and vapor.

19. In an evaporator of the climbing film type, a heating casing, aplurality of relatively long vertical evaporating tubes therein of atype adapted for climbing film evaporation, a plurality of basal feedingchambers communicating with correspond ing groups of said tubes andinclosing depending ends of said tubes, a plurality of correspondingliquid receiving chambers communicating with the tops of said groups, acommon vapor outlet for all said liquid receiving chambers and pipeconnections enabling two or more such groups of tubes to be usedserially or in parallel for the upward passage of liquid therethrough.

20. An evaporator comprising a plurality of effects in multiple effectarrangement, one such effect receiving liquid from an earlier effect andbeing provided with means for causing such liquid to circulate upwardlythrough a plurality of groups of evaporator tubes in series said groupsbeing inclosed in a common heating chamber receiving vapors from saidearlier efiect.

21. In an evaporator, a plurality of effects in multiple effectarrangement, the last of said effects comprising a plurality of groupsof evaporating tubes in a common heating casing and pipe connections forallowing liquid from the next preceding effect to be circulated upwardlyeither serially or in parallel through two or more such groups.

22. In an evaporator, a plurality of efiects in multiple effectarrangement, the last of said efi'ects comprising a plurality of groupsof evaporating tubes in a common heating casing and pipe connections forcausing liquid from the next preceding effect to circulate upwardlythrough two such groups and pipe connections to transmit liquid upwardlythrough another such group and thence to the feed inlet of the firsteffect in series.

23. In an evaporator, a plurality of effects in multiple efiectarrangement treating liquid in series and means for transmitting liquidover a portion of the heating elements of the last of said eliects, andthence to the feed inlet of the first effect in series.

24. In an evaporator of the climbing film type, a plurality ofrelatively long vertical evaporating tubes, a heating casing surroundingsaid tubes, individual feeding means for supplying a plurality of groupsof said tubes, a vapor hood surmounting the tops of said tubes,transverse vertical partitions in said hood forming a number ofsubchambers corresponding to said groups of tubes, a transverse septumspaced away from the hood walls and forming tops to said subchambers, aplurality of vertical angle irons disposed below said septum in the pathof liquid and vapor discharged from each subchamber against the hoodwalls, and a plurality of vertical angle irons disposed above saidseptum in the path of vapor recoiling from said hood wall and passingback to the center of said hood above said septum.

25. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basal feedchamber into which the tubes open, a partition dividing said chamberinto a plurality of subchambers corresponding to groups of said tubes, asurmounting hood having an exit for vapors and partitioned to formliquid receiving subchambers corresponding to said groups and pipeconnections by which liquid may be passed serially through a pluralityof such groups or through one such group while by-passing another group.

26.'In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating chamber, a basal feedchamber into which the tubes open, a partition dividing said chamberinto a plurality of subchambers corresponding to groups of said tubes, asurmounting hood having an exit for vapors and partitioned to formliquid receiving subchambers corre sponding to said groups and pipeconnections enabling the simultaneous employment of different groups inthe evaporation of liquids from different sources of supply.

27. In an evaporator, a plurality of groups of evaporating tubes,heating means common to all said groups, vapor removing means common toall said groups, individual means for supplying liquid to each suchgroup and individual means for removing concentrated liquid from eachsuch group.

28. In an evaporator, a plurality of groups of evaporating tubes, aheating casing surrounding all said tubes, individual liquid feedingmeans for each such group of tubes, individual liquid removing means foreach such group of tubes and common vapor removing means for all saidtubes.

29. In a climbing film evaporator, a plurality of groups of relativelylong vertical evaporating tubes, a heating casing surrounding all saidtubes, individual liquid feeding means at the base of each such group,individual liquid removing means at the top of each such group andcommon vapor removing means for all said tubes.

30. In a climbing film evaporator, a plurality of relatively longvertical evaporating tubes, an inclosing heating casing a basal feedchamber into which the tubes open, a partition dividing said chamberinto a plurality of subchambers corresponding to groups of tubes, asurmounting hood having an exit for vapors and partitioned to formliquid-receiving subchambers corresponding to said groups, individualliquid supply means for each such basal subchamber and individualliquid-removing means for each such liquid-receiving chamber.

31. An evaporator comprising a plurality of effects in multiple eifectarrangement, one such effect being provided with a plurality of groupsof tubes inclosed in a common heating casing, each such group havingconnections enabling individual feed of liquid thereto and removal ofconcentrated liquid therefrom.

32. In an evaporator of the climbing film type, a plurality of groups ofrelatively long vertical evaporating tubes, an inclosing heatingchamber, individual basal liquid supplying means for each said group,and an individual separator for liquid and vapor at the top of each suchgroup, each such separator having a liquid outlet and all saidseparators communicating with common vapor removing means.

33. In an evaporator of the climbing film type, a heating casing, aplurality of relatively long vertical evaporating tubes therein, basalfeeding means, a surmounting vapor-separating hood casing, means for discharging the Vapor and liquid emerging from the upper end of saidtubeslaterally within said hood, a plurality of vertical angle bars set inthe lateral path of said liquid and vapor, a horizontal septum abovesaidbars extending to a point short of the hood walls and anotherplurality of angle bars above said septum.

In testimony whereof, I affix my signature in the presence of twosubscribing witnesses.

PAUL KESTNER. Witnesses:

Liioiv PECKEL, VIo'roR KLAUszMANN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

, Washington, D. G.

